The electronics industry has seen significant integration in the functionality of radio frequency modules in the last 10 years. A module may now incorporate many semiconductor die and passive components, providing a complete functional system in a single integrated package, System in Package (SiP). This allows for ease of design into the final application. However, the electrical and mechanical interface between the radio system in the package and the antenna, which is needed to make it work, is still a burden to the designer. As well as meeting mechanical constraints, the designer must provide an effective antenna radiator that may require matching circuits to be positioned in the interconnection with the electronics package.
The semiconductor packaging industry fabricates modules in high volume multiple units. As many semiconductor modules as possible are covered with protective material in a single operation and the individual functional packages are then separated. Current practice includes the external attachment to electronics modules of antennas produced from sheet metal, for example by metal stamping or electro-chemical etching, but such solutions do not provide full integration and their connection to the internal electronic circuits is problematical.
Commercial pressures require the antenna to be ever lower in cost and to occupy less volume in the target device. A method by which the antenna can be embodied directly into the highly integrated “System in Package” (SiP) devices would be a great boon to the semiconductor industry. To gain widespread acceptance, the solution should incur minimum impact on existing standard semiconductor assembly processes.
It is known from US 2006/0256018 to provide SiP devices with integral fractal antennas. The antennas may be formed by incorporating an electrically conductive element in or upon a plastics mould that encapsulates the semiconductor package. The chip in the package can be connected to the conductive element by way of a capacitive or inductive coupling.
WO 2008/065640 also discloses chip packages, such as SiP devices, with integrated RF antennas. The antennas may be coupled directly to the chip by vias, or may be coupled through radiating coupling slots.